From 38010591a0fc3203f1cee45b01ab358b72dd9ab2 Mon Sep 17 00:00:00 2001 From: Tali Perry Date: Fri, 28 Mar 2025 19:32:50 +0000 Subject: [PATCH] i2c: npcm: Add clock toggle recovery During init of the bus, the module checks that the bus is idle. If one of the lines are stuck try to recover them first before failing. Sometimes SDA and SCL are low if improper reset occurs (e.g., reboot). Signed-off-by: Tali Perry Signed-off-by: Mohammed Elbadry Reviewed-by: Mukesh Kumar Savaliya Link: https://lore.kernel.org/r/20250328193252.1570811-1-mohammed.0.elbadry@gmail.com Signed-off-by: Andi Shyti --- drivers/i2c/busses/i2c-npcm7xx.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c index a31d9a6677a8..892e2d2988a7 100644 --- a/drivers/i2c/busses/i2c-npcm7xx.c +++ b/drivers/i2c/busses/i2c-npcm7xx.c @@ -2174,10 +2174,14 @@ static int npcm_i2c_init_module(struct npcm_i2c *bus, enum i2c_mode mode, /* Check HW is OK: SDA and SCL should be high at this point. */ if ((npcm_i2c_get_SDA(&bus->adap) == 0) || (npcm_i2c_get_SCL(&bus->adap) == 0)) { - dev_err(bus->dev, "I2C%d init fail: lines are low\n", bus->num); - dev_err(bus->dev, "SDA=%d SCL=%d\n", npcm_i2c_get_SDA(&bus->adap), - npcm_i2c_get_SCL(&bus->adap)); - return -ENXIO; + dev_warn(bus->dev, " I2C%d SDA=%d SCL=%d, attempting to recover\n", bus->num, + npcm_i2c_get_SDA(&bus->adap), npcm_i2c_get_SCL(&bus->adap)); + if (npcm_i2c_recovery_tgclk(&bus->adap)) { + dev_err(bus->dev, "I2C%d init fail: SDA=%d SCL=%d\n", + bus->num, npcm_i2c_get_SDA(&bus->adap), + npcm_i2c_get_SCL(&bus->adap)); + return -ENXIO; + } } npcm_i2c_int_enable(bus, true); -- 2.25.1